The Khlong Marui Fault, lying to the NNE of Phuket, has a strong geomorphic signal, with marked fault-strike parallel topographic ridges. The fault is ca. 150 km long with a 210-030º trend. The lithologies within the strike-slip zone mainly consist of vertical layers of mylonitic metapelites, migmatitic gneiss, mylonitic granite, pegmatites and cataclasites. The foliation and stretching lineations in ductile rocks indicate a dextral strike-slip displacement at mid- to upper-crustal levels. Pegmatites cross-cut the mylonitic foliation but are in turn sheared at their margins, indicating synkinematic emplacement. Although clear age-constraints are still lacking, the dextral strike-slip kinematics of the Khlong Marui fault is likely to be related to the escape tectonics arising from the India-Asia collision.